Island



(No Model.) 7

v s. W. WARVDWELL, Jr.

SHUTTLE FOR SEWING MACHINES. No. 396,631. Patented Jan. 22, 1889.

UNITED STATES ATENT tlrricn.

SHUTTLE FOR SEWING MACHINE$.

SPEOIFIUATION forming part of Letters Patent No. 396,631, dated January 22, 1889. Application filed June 11, 1887. $erialNo.241,0 L3. (No model.)

To (vZZ whom it may concern.-

Re it known that I, SIMON W. WARDWELL, J12, a citizen of the United States, and a resident of Providence, in the county of Providence and State of Rhode Island, have i11- vented certain new and useful Improvements in Se-wing-hjlachine Shuttles, of which the following is a specification.

This invention relates to shuttles for lockst-itch sewing-machines; and it consists in cer tain improvements whereby the danger of the thread pushing out between the bobbin and its holder or case when it overruns, after being jerked by the act of tightening the stitch, is prevented, and, further, in an improvedconstruction whereby a regular tension may be maintained upon the thread as it passes from the shuttle.

Figure 1 is a face view of a shuttle, enlarged, embodying my improvements. Fig. 2 is a section on the line 2 2, Fig. 1. Figs. 3 and 4 show modifications.

In the description of my invention I shall refer only to such parts as enter therein orare necessary to a proper understanding thereof.

The letterA designates the shuttle-body, which is hollow to receive the bobbin B, and is provided with an annular flange, a, which assists in confining the bobbin in the usual manner.

Pivoted at c, in an aperture provided therefor in the shuttle-body, is the tension-leverC, which covers the end of the recess in which the bobbin is placed, and which is provided with flanges a, to confine the latter therein. This lever is adapted to be turned back upon its pivot to permit the insertion or removal of the bobbin, as is usualin this class of shut tles. The heads b Z) of the bobbin move in close proximity to the walls of the case or chamber in which it lies; but between the two heads the walls of the chamber, which, as shown herein, is formed of the body and the tension-lever, are cut away, forming a recessor groove,D, extending around the inner wall of the bobbin-chamber beyond the plane of the bobbin when completely filled. This recess or groove forms two annular shoulders or faces, 3 4, in the bobbin-case, which extend completely around the bobbin, each substantially in the same plane or in line with the inner edge or face, 5, of the adjacent bobbinhead. This construction avoids the danger of the thread pushing out between the heads of the bobbin and the flanges a a when it loosens up by reason of the bobbin overrunning by permitting the portions of the uncoiled thread to lie in the open space formed by the annular groove I), as is illustrated in Fig. 2.

The short arm of tension-lever (J is borne upon by the tension-spring E, which is fiat and lies upon the side of the body A opposite to the lever, its end 6 being bent inward to effect a proper engagementwith the lever, the body at this point being shown as perforated to permit this engagement.

Th e tension-adj usti n g screw 1 passes loosely through a lug or seat, G, provided therefor, or through a portion of the body, and engages by a screw-connection with spring E. At the point of engagement with screw F the spring is provided with a perforated boss or stud, e, which lies in an aperture provided therefor in the shuttle-body, which is of such depth as to allow the necessary adjustment around the fulcrum-point of the spring where it bears against the outer face of the body. The thread passes from the bobbin around the screw, which is near its upper end grooved to guide it, and thence between the tension-lever near its free end and body to the place of delivery. The tension on the thread is maintained by the spring E, kept under tension by screw F, which bears against the short end of the lever and forces it down upon the thread. By this arrangement I obtain a perfeet shuttle-tension, as no possible variation in the size of the bobbin-thread will make any appreciable difference in the resistance to its flow. Knots, even, may be tied in this thread without in any wise impairing the appearance of the stitch.

For the sake of a better understanding of the operation of this part of my invention, I will suppose that the distance from 2 (the bearing or fulcrum of spring E) to 3 (where the power of the adjusting-spring is applied) is but one-ninth the distance from 3 to 4,. (the point where the spring engages with the short arm of lever 0,) and that the distance from 4 to 5 (the fulcrum-point of lever O) is but one-eighth the distance from 5 to G (where the lever bears upon the thread;) hence it is that the movement at S will. be but one seventysecond of the amount of movement at (5. As the average size of the thread used in the bobbin is but one one-hundredth of an inch in diameter, and a knot tied therein would only double its size or .increase it one onehundredth of an inch, it follows that the movement at 3, should a knot or other irregularity pass from the bobbin, would be only one seventy-second of one one-hundredth of an inch or one seventy-two hundredths of an inchan amount so small as to produce no appreciable effect even on the finest sewing.

The figures which I have given are merely for the sake of illustration, but are approximately correct.

It will thus be seen that by my invention I have produced a shuttle in which the difiiculty heretofore experienced from the thread being caught when it became uneoiled is entirely overcome, and in which I am enabled to maintain a uniform tension on the thread notwithstanding irregularities therein.

I am aware that a reciprocatii'ig shuttle has been provided with a hinged frame adapted to retain. the spool in place, made of two strips of thin sprin -steel connected together at one end and hinged to the shuttle, and at their opposite ends connected by a spring, which, on being tightened, will bow out one side of the frame and cause the thread to be bound between it and the shell of the shuttle.

\Vithout limiting myself to the exact construction of the parts shown, what I claim is 1. A shuttle-case having two inner shoulders extending entirely around the bobbin, substantially in line with the inner edges or faces of the bobbin-heads, substantially as described.

2. A shuttle-case having flanges A, to retain the bobbin, and two inner shoulders eX- tending entirely around the bobbin, substantially in line with the inner faces of the bobbin-heads, the case being recessed between the shoulders to form an annular recess entirely around the bobbin to receive the uncoiled thread, substantially as described.

3; A shuttle having a recess for the reception of a bobbin, provided with a tensionlever pivoted near one end mounted on one side of the body and having its other end arranged to bear on the thread, and a spring mounted at the side of the body opposite the lever, its long end bearing against the short end of said lever, and an adj usting-serew engaging with and regulating said spring, whereby the said lever is made to bear with more or less pressure upon the thread, sub stantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

SIMON V. IVARDWELL, J R.

Witnesses:

. JEFFERSON ALDRICH,

PHILIP L. A. MILLER. 

